Estimation of lymph node metastasis by size in patients with intrathoracic oesophageal cancer

The preoperative evaluation of lymphatic metastasis in patients with oesophageal cancer is of vital importance in determining a therapeutic strategy. The aim of this study was to establish criteria for the preoperative diagnosis of lymph node metastases based on the size and shape of nodes.

Some 123 patients with intrathoracic oesophageal cancer were studied and 6822 nodes were obtained by extended lymphadenectomy. The nodes were classified anatomically and their size was measured by the operating surgeon during or immediately after operation. All were examined histologically and criteria for the diagnosis of metastasis were evaluated.

The size of the lymph nodes varied by anatomical site. Nodes were smallest in the neck and largest at the tracheal bifurcation. The cut-off value for the diagnosis of metastasis was 5 mm in the neck, 6 mm in the abdomen and 8 mm in the mediastinum, except for tracheal nodes. Lymph nodes 10 mm or larger tended to become spherical when involved by metastasis.

The incidence of metastasis in each lymph node can be estimated by its size. Discounting nodes less than 10 mm can lead to an underestimation of the stage of oesophageal cancer during preoperative evaluation.